Tone-Fading.. brauche Hilfe...

ok, keine Ahnung was "Code_Flags " sind....hab den Code zwischen diesen "Flags" gesetzt, hoffe das stimmt so:

int lautPin = 2;
int frequenz;

void setup() {
  
 Serial.begin(9600);
  frequenz = 400;     
}

void loop() {  

 delay(100);
 melodie1();
 delay(2000);
 if (frequenz >= 4000)
 {
 melodie2();
 delay(2000); 
}
}
void melodie1()
{
Serial.println("melodie1 Frequenz=");
 Serial.println(frequenz);
 delay(100);
 while (frequenz <= 4000)
 {
  tone(lautPin, frequenz);
  delay(100);
  frequenz = frequenz + 100;
 }
 
}
 void melodie2() 
{ 
 Serial.println("melodie1 Frequenz=");
 Serial.println(frequenz);
 delay(100);
  tone(lautPin, frequenz);
  delay(100);
  frequenz = frequenz - 100;
 
}